The present invention relates to a technique for managing computers, and in particularly to a technique for managing a plurality of computer resources.
In the field of information processing systems or datacenters in companies, the number of servers have been increased. With the above above-trend increase, an operational management cost of the servers has been increased.
In order to solve the above-mentioned problem, a technique has been known that the servers are virtualized, that is, the technique in which the server is virtualized is that a plurality of virtual servers can be operated by a single physical server. Specifically, resources such as processors (CPU: Central Processing Unit), memories, etc. provided in the physical server are divided, and these divided resources in the physical server are allocated to the plurality of virtual servers, respectively. The plurality of virtual servers are then operated by the single physical server simultaneously.
In these days, the processing performance of CPU has been progressed and the cost of resources such as memory has been come down, therefore, the demands regarding the technique of virtualizing the servers have been increased.
Further, the technique of virtualizing the servers not only provides a merit of such that the plurality of virtual servers can be operated by the single physical server, but also provides a merit of such that the resources in the physical server can be used effectively by executing a workload management using the plurality of virtual servers.
Here, the workload management means that a resource amount of the physical server, to be allocated to the virtual servers, is varied in response to a condition of a load on the physical server etc. For example, when the load on a certain virtual server becomes high, the resources of the physical server, which are allocated to a lowly load virtual server being operated in the same physical server, are allocated to a highly load virtual server. In this way, the resources of the physical server can be used effectively.
Further, in the case of using a resource pool, the resource amounts to be allocated can be managed collectively for the virtual servers which are grouped. In this way, a total resource amount allocated to the grouped virtual servers is set, and the resources of the total resource amount, which are set in between the grouped virtual servers, can be used in share. A user of the resource pool can extend the size of the virtual servers and can also newly create virtual servers within the total resource amount of the resource pool.
Further, an allocation policy of the resource to be applicable to the groups can be set. For example, the virtual server can be set in such that the resources are allocated in priority to the virtual server when the resources are competed within the virtual servers in the group. Furthermore, the resources are allocated not only to occupy the group, but also share between the groups. When competing the resources shared between the groups, the allocation policy can be set to the group such that the resources are allocated in priority to the group.
In this way, by executing the resource management of the resource pool, the resources in the plurality of physical servers can be used effectively. Such above-mentioned technique has been proposed as JP-A-2007-272263, JP-A-2-122363, and a document found on Internet <URL: http://www.vmware.com/files/jp/pdf/vi3—35—25_u2_resource_mgmt_ja.pdf> VMware, Inc “resource management guide”, online, Apr. 17, 2009